Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FHB > Endocrinology 7- HPA Axis pt 1 > Flashcards

Endocrinology 7- HPA Axis pt 1 Flashcards

1
Q

5 cell types of anterior pituitary

A 
somatotrope
gonadotrope
corticotrope
thyrotrope
lactotrope
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the hypothalamic hormone that is released to start the HPA axis

A

CRH/CRF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Pituitary hormone released in HPA axis

A

ACTH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Adrenal hormones released as part of the HPA axis

A

Cortisol, aldosterone, androgens, catecholamines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where is CRH released from in hypothalamus?

A

Parvocellular neurons of PVN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What gene is ACTH on?

A

POMC gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In what manner is CRH released?

A

pulsatile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

half life of CRH

A

5min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Receptor for CRH

A

Highest affinity binding is to CRH R1 in anterior pituitary, CRh R2 binds higher affinity to other things. But CRH can activate at least 5 different G proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is ACTH synergized with AVP?

A

AVP synergizes with corticotropes to make sure there is a proper stress response - osmoregulatory and stress is appropriately responded to

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

ACTH- what two hypothalamic hormones regulate its generation?

A

CRH and AVP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the precursor to ACTH

A

POMC (pro opiomelanocortin

When this is broken down there are beta endorphans, alpha msh, acth, and more

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What receptor does ACTH bind with highest affinity to?

A

Melanocortin 2 receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What receptor does ACTH bind with lower affinity to – what is the consequence of this

A

MC1R – high ACTH levels can lead to hyperpigmentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How can cortisol impact ACTh release

A

negative feedback on anterior pituitary corticotrophs and CRH
hypothalamic neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Does ACTH affect immediate, long term, or itnermediate term outcomes?

A

All 3 – in long term, it affects size and complexity of organelles and number of cells, other effects are intermediate or short term

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

middle of adrenal gland is called what

A

medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What kind of tissue is the middle of the adrenal gland derived from

A

neural tissue - you get direct sns innevation here

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what kinds of hormones are made in the medulla of the adrenal gland

A

catecholamines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

3 regions of adrenal cortex

A

zona glomerulosa, zona fasiculata, zona reticularis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

hormone type made in zona glomerulosa

A

mineralocorticoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

hormone type made in zona fasiculata

A

glucocorticoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

hormone type made in zona reticularis

A

weak androgens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

as opposed to the medulla, which makes catecolamines, what kind of hormone does the adrenal cortex make?

A

steroid hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the trickle down effect of the adrenal gland?

A

The blood supply of the medulla travels down from cortex - this is important for the conversion of norepinephrine to epinephrine

26
Q

What hormone is required to get epinephrine from norepinephrine

A

cortisol

27
Q

zona fasiculata makes what hormone

A

cortisol (or corticosterone in rodents)

28
Q

What kind of expression pattern does cortisol show

A

circadian rhythm - peak is around 8AM, but as you get older you can shift rhythm based on environment

29
Q

How is cortisol usually transported in blood

A

bound to transport proteins (CBG) and must dissociate to be active - around 5% of cortisol is free

30
Q

how much cortisol is free in blood

A

5%

31
Q

Can the cortisol binding globulin also bind to other things

A

yes, aldosterone but it is much less higher affinity for it

32
Q

how does estrogen impact free cortisol

A

it increases CBG, so there is less free cortisol

33
Q

where is the glucocorticoid receptor

A

inside the cell

34
Q

How does glucocorticoid receptor work?

A

cortisol binds, chaperones dissociae from glucocorticoid receptors, and GR-Cortisol complex impacts gene transcription

35
Q

in absence of cortisol, how does the Glucocorticoid receptor (GR) exist

A

bound to chaperones in cytoplasm

36
Q

what enzyme is importnant for increasing local cortisol concentrations

A

11B HSD 1

37
Q

7 key functions of cortisol

A 
Metabolism - glucose mobilizing
Muscle - proteolysis
Adipsoe tissue - lipolysis
Immune/inflammation - suppression
bone - resorption
cardiovascular - maintain CO, increase arteriolar tone, decrease endothelial permeability 
CNS
Maturation of fetus -- important in lung dvelopment and surfactants
38
Q

Metabolic actions of cortisol

A

potent counter- regulatory hormone to insulin

mobilizes energy stores, increase plasma glucose (glucocorticoid)

39
Q

What does cortisol do to glucose balance

A

increase gluconeogenesis and plasma glucose levels

40
Q

how does cortisol impact fat

A

lipolysis

redistribution of fat (abdominal obesity but depletion of subcutaneous fat)

41
Q

how dos cortisol impact protein

A

proteolysis

42
Q

Insulin is an anabolic hormone, how does cortisol compare?

A

it is oppository - it is catabolic

43
Q

How does cortisol impact how glucose can be taken up into cells

A

decreases GLUT4 insertion into membrane

44
Q

What key enzymes are impacted by cortisol for gluconeogenesis

A

PEPCK
Tyrosine aminotransferase
glucose 6 phosphatase

45
Q

How does cortisol impact amino acid uptake into muscle cells

A

inhibits it

46
Q

how does cortisol impact muscle breakdwn? What is it doing?

A

increases transcription of an E3 ligase

47
Q

What would be the impact of chronic high glucocrticoids on muscle?

A

will eventually cause muscle weakness due to wasting as result of actions of cortisol on muscle

48
Q

Cortisol increases expression of what three key genes with regard to lipolysis

A

MgII, Lipe, and Angpt14 – these are lipases that will all activate hormone sensitive lipase (you’re going to be mobilizing fat)

49
Q

Glucocorticoid receptor does what to NFkB

A

inhibits it - this is through increasing the IkB transcription - this then prevents NFkB nuclear translocation – thus decreasing local inflammatory responses

50
Q

How does cortisol impact the immune system

A

Stimulate anti-inflammatory cytokines, inhibit pro inflammatory cytokines, inhibit PLA and decrease PG’s , leukotrines, and thrombocytes. You also get vasodilation, and neutrophil number is increased but nonfunctional - therefore, you could suppress inflammation when using glucocorticoids, but risk reducing ab production as well

51
Q

how does cortisol impact bone

A

IGF-I receptors are going to be inhabited as well as intestinal calcium absrption going up so cortisol impacts calcium in many ways -

Inhibits intestinal calcium absorption therefore - transcellular transport
Inhibits bone formation and decreases IGF-I receptors
Increases bone resorption, activation of osteoclasts

52
Q

How does cortisol impact cardiovascular health

A

during physical stress we want blood to flow to heart and brain, away fro periphery. Therefore it stimulates RBC production and maintains responsiveness to catecholamine pressor effects – constrict peripheral vessels via a-adrenergic receptors, dilate coronary arteries in heart via beta adrenergic receptors is what we want. Because of the stimulation of these receptor types, glucocorticoid excess = increased blood pressure, hypertension. However, cortisol is requried to maintain vascular integrity and reactivity

53
Q

Cortisol impact on CNS

A

Emotional response - anxiety, depression, nervousness, panic, feeding behavior, rage and aggression

perception

Negative feedback on CRH and ACTH release

54
Q

Cushing disease vs cushing syndrome

A

cushing disease = excessive cortisol secretion due to ACTH secreting pituitary adenoma
cushing syndrome - symptoms of cushing ddisease due to other cuases than pituitary adenoma

55
Q

some causes of cushing syndrome

A

exogenous glucocorticoid therapy
small lung cell carcinoma that secretes acth
adrenal tumor

56
Q

Changes to body that occur in cushing syndrome and cushing disease

A

Changes in body fat distribution (moon fase, buffalo hump, abdominal obesity, thin skin, bruising), inhibition of intestinal calcium absorption leading to osteoporosis, hypertension possibly due to excess glucocorticoids activating MR, glucose intolerance due to antagonism of insulin action, and purple striae from fragile skin stretching over increased abdominal fat, and vessels hemorrahging into striae

57
Q

When is glucocorticoid therapy given

A

medical emergencies to treat sepsis, asthma, autimmune diseases

Chronic usage for anti-inflammatoyr, immunosuppressive, adrenal insufficiency, pre=term infants to help with lungs

You MUSt wean off if you are giving chronically

58
Q

Adrenal insufficiency

A

Failure of adrenal gland, can be primary adrenal failure or secondary failure (addison’s disease, or secondary)

59
Q

Addison’s disease

A

autoimmune disease (primary disease) where adrenal cortex is attacked, first symptoms are related to ones of adrenal cortex

60
Q

Secondary adrenal insufficiency

A

failure to secrete CRH or ACTH - usually ACTH – most common cause is sudden cessation of glucocorticoid therapy

FHB (54 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions